renderer_vulkan: Add conditional rendering control setting

Adds user option to disable Vulkan conditional rendering, which can fix
flickering objects in some games caused by rapidly toggled draw calls.

Changes:
- Add use_conditional_rendering setting (default: enabled)
- Guard conditional rendering functions with setting check using [[unlikely]]
- Early exit in Pause/Resume and Compare functions when disabled

Disabling this in Graphics (Advanced) fixes flickering at cost of performance.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/citron/configuration/shared_translation.cpp

@@ -230,6 +230,10 @@ std::unique_ptr<TranslationMap> InitializeTranslations(QWidget* parent) {
               "unlocked."));
     INSERT(Settings, barrier_feedback_loops, tr("Barrier feedback loops"),
            tr("Improves rendering of transparency effects in specific games."));
+    INSERT(Settings, use_conditional_rendering, tr("Use conditional rendering"),
+           tr("Enables conditional rendering based on query results.\n"
+              "Disabling this can fix flickering objects in some games but may impact performance.\n"
+              "Try disabling if you see objects appearing and disappearing rapidly."));
 
     // Renderer (Debug)
 

src/common/settings.h

@@ -469,6 +469,8 @@ struct Values {
                                                 Category::RendererAdvanced};
     SwitchableSetting<bool> barrier_feedback_loops{linkage, true, "barrier_feedback_loops",
                                                    Category::RendererAdvanced};
+    SwitchableSetting<bool> use_conditional_rendering{linkage, true, "use_conditional_rendering",
+                                                      Category::RendererAdvanced};
 
     Setting<bool> renderer_debug{linkage, false, "debug", Category::RendererDebug};
     Setting<bool> renderer_shader_feedback{linkage, false, "shader_feedback",

src/video_core/renderer_vulkan/vk_query_cache.cpp

@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include <cstddef>
@@ -1290,6 +1291,9 @@ void QueryCacheRuntime::EndHostConditionalRendering() {
 }
 
 void QueryCacheRuntime::PauseHostConditionalRendering() {
+    if (!Settings::values.use_conditional_rendering.GetValue()) [[unlikely]] {
+        return;
+    }
     if (!impl->hcr_is_set) {
         return;
     }
@@ -1301,6 +1305,9 @@ void QueryCacheRuntime::PauseHostConditionalRendering() {
 }
 
 void QueryCacheRuntime::ResumeHostConditionalRendering() {
+    if (!Settings::values.use_conditional_rendering.GetValue()) [[unlikely]] {
+        return;
+    }
     if (!impl->hcr_is_set) {
         return;
     }
@@ -1314,6 +1321,12 @@ void QueryCacheRuntime::ResumeHostConditionalRendering() {
 
 void QueryCacheRuntime::HostConditionalRenderingCompareValueImpl(VideoCommon::LookupData object,
                                                                  bool is_equal) {
+    // Early exit if conditional rendering is disabled by user
+    if (!Settings::values.use_conditional_rendering.GetValue()) [[unlikely]] {
+        impl->hcr_is_set = false;
+        return;
+    }
+
     {
         std::scoped_lock lk(impl->buffer_cache.mutex);
         static constexpr auto sync_info = VideoCommon::ObtainBufferSynchronize::FullSynchronize;
@@ -1340,6 +1353,12 @@ void QueryCacheRuntime::HostConditionalRenderingCompareValueImpl(VideoCommon::Lo
 }
 
 void QueryCacheRuntime::HostConditionalRenderingCompareBCImpl(DAddr address, bool is_equal) {
+    // Early exit if conditional rendering is disabled by user
+    if (!Settings::values.use_conditional_rendering.GetValue()) [[unlikely]] {
+        impl->hcr_is_set = false;
+        return;
+    }
+
     VkBuffer to_resolve;
     u32 to_resolve_offset;
     {